[Bi₆Mo₃(CO)₉]^4-: a multiple local σ-aromatic cluster containing a distorted Bi₆ triangular prism

Area of Science:

• Inorganic Chemistry
• Solid-State Chemistry
• Materials Science

Background:

• Zintl clusters are anionic atomic clusters with unique electronic properties.
• Bismuth-based clusters are of interest due to their potential for novel electronic and structural motifs.
• Understanding the electronic structure of complex clusters is crucial for predicting their properties.

Purpose of the Study:

• To synthesize and characterize a novel Zintl cluster containing a bismuth core.
• To investigate the electronic properties and bonding characteristics of the synthesized cluster.
• To explore the presence of aromaticity in a distorted cage cluster.

Main Methods:

• Single-crystal X-ray diffraction for structural characterization.
• Quantum chemical calculations (e.g., DFT) to analyze electronic structure and bonding.
• Spectroscopic techniques for confirmation of cluster formation.

Main Results:

• Successful synthesis and structural determination of the first Zintl cluster with a distorted Bi6 triangular prism core: [Bi6Mo3(CO)9]4-.
• Quantum chemical calculations confirmed the presence of multiple local sigma-aromaticity within the distorted cage structure.
• The electronic structure analysis provided insights into the bonding interactions within the cluster.

Conclusions:

• The discovery of [Bi6Mo3(CO)9]4- expands the known family of Zintl clusters.
• The presence of local sigma-aromaticity in a distorted cage highlights unusual electronic delocalization.
• This work provides a foundation for designing new bismuth-containing materials with tailored electronic properties.